A facile aptamer-regulating gold nanoplasmonic SERS detection strategy for trace lead ions

The as-prepared gold nanoparticle (AuNP) exhibited strong catalysis of the nanoreaction between H2O2 and HAuCl4 to form gold nanoparticles (GNP) with nanoplasmonic surface-enhanced Raman scattering (SERS) at 1614 cm(-1), in the presence of Victoria blue B (VBB) molecular probes. Upon addition of the Pb2+ aptamer, it adsorb on AuNP surface to inhibit the its nanocatalysis, and the SERS, surface plasmon resonance (SPR) absorption and resonance Rayleigh scattering (RRS) decreased due to the redox product of GNP nanoplasmonic effect decreasing. When Pb2+ was added, the aptamer combined with it to form a very stable G-quadruplex and free AuNPs, which lead to the catalysis recovering, and the absorption, RRS and SERS intensity enhanced linearly. Hereby, a new and simple, sensitive and selective gold nanoplasmonic SERS platform was established for Pb2+, based on the aptamer-regulating GNP nanoplasmonic SPR effect. (c) 2017 Elsevier B.V. All rights reserved.